Which of the following is a conjugate acid-base pair?
A. H2SO4, H2SO3
B. NH3, NO2
C. CH3OH, CH3COOH
D. HF, H2F
E. NH3, NH4+
HA is an acid. A^- is the conjugate base BECAUSE A^- will add a hydrogen ion to become an acid.
Which of those pairs can you take away a H^+ to make the base (or add a H^+ to form the acid)?
Hint #1. Look at the last pair.
NH3, NH4^+. Note I can take a H^+ away from NH4^+ to form NH3. I can add a H^+ to NH3 to form NH4^+. So this is a base-conjugate acid pair. Can you do that with any of the others?
To identify a conjugate acid-base pair, we need to understand the concept of acids and bases and their behavior in chemical reactions. An acid is a substance that donates a proton (H+) in a chemical reaction, while a base is a substance that accepts a proton.
Let's go through the options provided:
A. H2SO4, H2SO3
H2SO4 is a strong acid that donates a proton, while H2SO3 is its corresponding conjugate base that can accept the proton. So, they form a conjugate acid-base pair.
B. NH3, NO2
NH3 is a base that accepts a proton, while NO2 is not directly related in acid-base behavior to NH3. They do not form a conjugate acid-base pair.
C. CH3OH, CH3COOH
CH3OH is a weak acid that can donate a proton, while CH3COOH is its corresponding conjugate base that can accept the proton. So, they form a conjugate acid-base pair.
D. HF, H2F
HF is a weak acid that donates a proton, while H2F does not behave as a base. They do not form a conjugate acid-base pair.
E. NH3, NH4+
NH3 is a base that accepts a proton, while NH4+ is its corresponding conjugate acid that can donate the proton. So, they form a conjugate acid-base pair.
Therefore, the correct answer is:
A. H2SO4, H2SO3